Im no expert on networking meetings, so please feel free to correct me anyone if im wrong,
but there appear to be 3 main types of business networking groups/ meetings.
What are called BNI Groups - Which call themselves chapters, you have to pay a membership fee to join (although you can be invited to attend up to twice as a guest before you join) and then you will need to pay a fee (between £10- £20) for each meeting you attend.
Members rules are usually very strict and you are only allowed to miss a maximum of 3 meetings a year or you are kicked out. Members are also expected to provide referals (leads) for all other members every meeting. If you dont have leads for other, then you dont have them, but it can be very uncomfortable when it comes to your turn, and everyone looks at you and say you dont have any. It can be great for some, but it might not be the right kind of group for you. You can read all about BNI networking on their website here:
http://www.bni.com/Paid membership networking groups - Which are very similar, except they are not called chapters and they usually tend to be a little more informal and less rigid. Though you may need to work a little harder to get referals. Generally you still ned to pay for membership to the group and then pay for each meeting.
Open or Free networking groups - These are sometimes better attended, and the great thing is that you can come and go as you please to which ever meetings suit you without feeling preasured to attend meetings that are not convenient for you. Again you simply pay to attend. An example of an open or free membership Networking group is:
http://www.networking-on-sea.co.ukIt is always worth making sure that which ever meeting or group you choose to asttend you book it and pay inadvance rather than on the door as that way you will get your details down on the networking list that gets given to all in attendance. It gives you a better chance of producing leads and valuable connections.
As for experiences / Pros / Cons I will leave that to others to comment...